1. Field of the Invention
The invention relates to a vacuum cleaner and a method for reducing noise generated thereby, and, more particularly, to a vacuum cleaner, which has a discharge flow path and a discharged-air filter optimally positioned to reduce noise.
2. Description of the Related Art
Generally, a vacuum cleaner is an apparatus, which cleans a room in such a manner that foreign matter such as dust and loose debris is drawn in along with air into a body by generating suction force, and removed through a dust collection unit and the like within the body.
Referring to FIG. 1, a conventional vacuum cleaner includes a body 1 defining an outer appearance, a blower fan unit 2 positioned within the body 1 to generate suction force, and a dust collection unit 3 to filter foreign matter from air drawn into the body 1. The vacuum cleaner is operated in such a manner that suction force is generated by the blower fan unit 2 to draw foreign matter such as dust along with air into the body 1, and only the air is discharged to an outside of the body by filtering the foreign matter from the air via dust collection unit 3 positioned in the body 1, thereby cleaning a room.
The blower fan unit 2 of the conventional vacuum cleaner includes a blower fan 2a to generate suction force while rotating, and a motor 2b to rotate the blower fan 2a. The blower fan 2a and the motor 2b are positioned to have a rotational axis disposed longitudinally in a front and rear direction such that air is drawn in from a front side, and is then discharged to a rear side. After being discharged to the rear side, the air is guided along a discharge flow path 6, passes through a discharged-air filter 5, and is then discharged to the outside of the body 1 via an air vent 4 positioned at a rear upper portion of the body 1.
In such a vacuum cleaner, noise is generated due to various causes. Specifically, noise generated by rotation of the motor 2b, noise generated when air passes through the discharged-air filter 5 via the discharge flow path 6, and noise generated by friction between the air flowing at high speed within the discharge flow path 6 and a duct 7 defining the discharge flow path 6 are causes for the majority of the noise generated from the vacuum cleaner.
However, the conventional vacuum cleaner has problems in that, since the length of the discharge flow path 6 from a discharge port 8 of the blower fan unit 2 to the air vent 4 is short, noise generated by rotation of the motor 2b is transferred to the outside of the body 1 without being sufficiently reduced, and in that, since the length from the discharged-air filter 5 to the air vent 4 is also short, the noise generated when air passes through the discharged-air filter 5 via the discharge flow path 6 is also transferred to the outside of the body 1 without being sufficiently reduced.